Many medical devices, such as catheter systems for establishing intravenous therapy, include needles that are inserted into patients. By contacting body tissue and fluids such as blood, such needles carry biohazard risks including cross-contamination and transmission of blood-borne diseases, as well as accidental needle sticks or punctures inflicted on a user of the medical device or any other handlers of used medical instruments. Thus, there is a need in the medical field to create an improved safety needle system. This invention provides such an improved safety needle system operable with a medical device.